A model of temperature dynamics was developed as part of a general model of activated-sludge reactors. Transport of heat was described by the one-dimensional, advection-dispersion equation, with a source term based on a theoretical heat balance over the reactor. The model was compared to several reference models, including a tanks-in-series model and the dispersion model with heat components ne...

Accurate modeling of the energy balance of a snowpack requires good estimates of the snow surface temperature. The snow surface temperature allows a balance between atmospheric heat fluxes and the conductive flux into the snowpack. While the dependency of atmospheric fluxes on surface temperature is reasonably well understood and parameterized, conduction of heat from the snow surface into the ...

Usually the energy balance equation is used to estimate evapotranspiration. To calculating the potential evapotranspiration for long periods of time (more than a day), soil heat flux is assumed equal to zero. But in a catchment, the energy balance equation should be in terms of actual evapotranspiration is less than the potential. In this state, the amount of soil heat flux is not equal to zero...

In this manuscript we present the design and construction of a pilot system that incorporates both a heat exchanger component and a cooling tower add-on. This prototype was constructed in order to simulate real industrial open recirculating cooling systems. Heat exchanger planning was realized using mass and energy balance. The application of mass balance was realized under permanent (static) c...

1. Twenty-seven energy and protein balances were done using nine cross-bred (Brown Swiss times Sahiwal) mature bullocks in a series of three balance trials. The bullocks were fed 75, 100 and 125 percent of the metabolizable energy (ME) and digestible crude protein standard values recommended by the (US) National Research Council (1966). Heat production was estimated by indirect calorimetry, by ...

a mathematical model of a continuous reheating furnace has been developed to identify the design and operating parameters that significantly affect furnace performance. in this study, the furnace is modeled 3 dimensionally and themonte carlomethod is used to find the overall absorption factor. the overall absorption factor is then used to calculate the energy balance for furnace walls, the gas,...

The rate of evaporative cooling was calculated from the rate of mass loss in starlings (Sturnus vulgaris) during 90 min flights in a wind-tunnel. Evaporative heat loss ranged from 5% of the metabolic rate at -5 degrees C to 19% of the metabolic rate at 29 degrees C. Radiation and convection accounted for the balance of the heat loss. On average, starlings dehydrated during flights at all temper...

10 Results from the first international urban model comparison experiment (PILPS-Urban) suggested that models which 11 neglected the anthropogenic heat flux within the surface energy balance performed at least as well as models that 12 include the source term, but this could not be explained. The analyses undertaken show that the results from PILPS13 Urban were masked by the signal from includi...

An enthalpy-balance fuel-grain regression model is presented. The regression model, based on the longitudinally averaged fuel recession rates, is shown to accurately predict the chamber pressure, thrust and specific impulse performance of small and medium scale hybrid rocket motors. The key to the model predictions is the longitudinal enthalpy balance between the fuel grain heat of ablation and...

A two-dimensional, non-isothermal model of a proton exchange membrane fuel cell was implemented to elucidate heat balance through the membrane electrode assembly (MEA). To take local utilization of platinum catalyst into account, the model was presented by considering the formation of agglomerated catalyst structure in the electrodes. To estimate energy balance through the MEA, various modes of...